S4 engine in 5K?

A friend of mine said that an S4 engine from say a '94 or so,
would not fit my '87 5kTQ 5-speed gearbox, and that to drop an S4
engine in this car, the S4 gearbox would have to come along for
the ride. Sounds nice, but waaaay pricy.
Listmembers can confirm or deny????
Steve Barnes